Method of making a tobacco substitute material

ABSTRACT

A tobacco substitute is prepared by dry-grinding pieces of nonwoody or low-wood plants to a particle size below 150 microns, thereafter wet-milling the powder to produce a slurry with a particle size of the powder below 50 microns, adding a binder such as sodium carboxymethyl cellulose to the mixture together with a plasticizer and, possibly, mineral fibers and burning controllers. The slurry is cast into a film and dried, preferably with after-moisturization to a final moisture content of the foil between 1 and 15 percent by weight. Any toxic substances contained in the botanicals are removed by steam distillation or solvent extraction prior to forming the composition into a dried film.

United States Patent [191 Buchmann et al.

[ METHOD OF MAKING A TOBACCO SUBSTITUTE MATERIAL [75] Inventors: Paul Buchmann, Basel, Switzerland;

Monique Beringer, Saint Louis, France [73] Assignee: Tamag Basel AG, Basel, Switzerland [22] Filed: Nov. 1, 1971 [21] Appl. No.: 194,654

[30] Foreign Application Priority Data Nov. 3, 1970 Luxembourg 61985 [52] US. Cl. 131/2, 131/140 C [5 I] Int. Cl. A24b 03/14, A24b 15/00 [58] Field of Search l3l/2, 15, 17, 140-144 [56] References Cited UNITED STATES PATENTS I 2,707,472 5/1955 .lurgensen, Jr. et al... 131/15 2,769,734 11/1956 Bandel 13l/15 2,809,904 10/1957 Koree 131/2 3,003,895 10/1961 Grunwald 131/17 3,106,209 10/1963 Torigian 131/2 3,203,432 8/1965 Green et al. 131/140 C June 28, 1974 OTHER PUBLICATIONS The Dispensatory of the United States of America" (text), Osol-Farrar, Pub. by J. B. Lippincott Co., 25th Edition, page 1381 cited.

Primary Examiner-Melvin D. Rein Attorney, Agent, or FirmKarl F. Ross; Herbert Dubno [57] ABSTRACT A tobacco substitute is prepared by dry-grinding pieces of nonwoody or low-wood plants to a particle size below. 150 microns, thereafter wet-milling the powder to produce a slurry with a particle size of the powder below 50 microns, adding a binder such as sodium carboxymethyl cellulose to the mixture together 1 Claim, 1 Drawing Figure PATEuTl-jmuuze m4 HARMFUL SUBSTANCES ADDITIVES PLANTS CUT GRIND DRY -3 GRIND DRY A GRIND WET WITHDRAW SPREAD A0 DRY 7 v MOISTENKW.

LOOSEN 1 METHOD OF MAKING A TOBACCO SUBSTITUTE MATERIAL FIELD OF THE INVENTION Our present invention relates to tobacoo substitutes and,-more particularly, to a tobacco-substitute foil and to a method of making same.

BACKGROUND OF THE INVENTION "stances from natural tobacco so as to create a product which hasa taste" or flavor upon smoking, which closely resembles that of natural tobacco but is free from all of the detrimental effects thereof. These investigations have produced low-nicotine and low-tar tobacco substitutes which are of poor smoking quality and havenot, therefore, proved to be commercially satisfactory. On the other hand, there have been researches into the creation of tobacco substitutes in the form of artificial tobacco. In these. systems, a fibrous substrate or a film-forming substrate is compounded with flavoring agents, essential oils, plant extracts and the like to approach the appearance, aroma and smoking taste of natural tobacco. Efforts along these lines have proved to be fruitless and the product isneither of satisfactory smoking quality nor capable of being processed into the forms in which smoking tobacco are desired.

For example, it has been suggested to impregnate organic substrates such as paper, plant leaves (e.g., lettuc'eleaves) and the like with tea extracts and to dry the product for use as tobacco substitutes. The taste and burning quality of the product is unsatisfactory and the presence of undesirable substances has rendered the substitute unhealthy. Finally, the processing of the substitute into'smoking tobacoo, e.g., by shredding, has been impeded or rendered difficult because of the nonelastic character of the product. To overcome these disadvantages, it has been proposed to admix the synthetic tobacco with natural tobacco, a step which has only returned the art to the original state, i.e., the use of natural tobacco with its known deleterious effects.

Another disadvantage of prior-art tobacco substitutes and methods of making same is the high cost of the substitute.

OBJECTS OF THE INVENTION It is the principal object of the present invention to provide an improved tobacoo substitute which will obviate the aforementioned disadvantages.

It is a corollary object of the invention to provide an improved method of making a more effective and satisfying tobacco substitute.

Another feature of the invention resides in the provision of a tobacco-substitute foil, and method of making same, which is of low cost, which can be easily processed and handled by existing tobacco-processing machinery and personnel, and which has an aroma and taste closely approximating those of natural tobacco SUMMARY OF THE INVENTION I It is our surprising discovery that the drawbacks of earlier systems can be avoided and a tobacco'like product obtained whichclosely approximates natural tobacco but has a controllable concentration or proportion of biologically active materials, when plant parts are comminuted at least in part by wet-milling to a particle size below l50 microns and preferably under 50 microns in a solids-to-water ratio of lzl to 1:10, thereby forming a slurry which is combined with a binder and plasticizer in predetermined critical concentrations, and then cast into a film or foil whose moisture content is established between I and 15 percent.

It is essential to the present invention that comminution of the botanicals which are to be used in accordance with the present invention, is effected to a particle size below microns. In other words, particles with a particle size of 150 microns or less are to be found in the slurry according to the present invention. Theslurry is subjected to wet-milling, a step which is also critical to the present invention, whereupon a criti' cal proportion of 0.5 to 3% by weight, of the dry botanicals, of a film-forming binder is admixed. The binder, according to the invention, is the sodium salt of carboxymethyl cellulose (CMC), this compound being represented by the formula NaCMC.

According to another essential feature of the invention, to the slurry is added I to 10% (by weight of the dry botanicals) of a' plasticizer which renders the composition hygroscopic, 0 to 4% (by weight of the dry botanicals) of mineral fibers to improve the structural integrity of the foil, 0 to 1% (by weight of the dry botanicals) of formate salts which have the effect of maintaining a uniform burning during smoking at a rate closely resembling that of natural tobacco, and O to 5% (by weight of the dry botanicals) of biologically active adclitives.

The term biologically active additives is used herein to describe components which are not naturally present in the composition but have an aromatic effect or a pharmacological effect and are supplied in order to improve taste, flavor or appearance, or are added as a treatment agent to reduce appetite, etc. Typical pharmacologically and biologically active substances which may be used in accordance with the present invention are described below.

We have also used herein the term fbotanical to describe the plant parts which may be employed in a system of the present invention. In general, the term is intended to refer to low-wood or nonwoody plant parts which may be from trees, shrubs, grasses and stalk plants and may be drawn from any part of the plant which is low in woody character. The effective parts of the plants include the leaves, blossoms, stalks, roots and stems. Of course, for the purposes of the present invention the term botanicals will be understood to exclude the tobacco plant and parts thereof.

We have also described the particle size of the plant parts which are used in accordance with the present invention as being of 150 microns and less or at most 150 microns. In this definition of particle size, it should be understood that all of the particles within the described range pass through a sieve of the indicated particle size. Thus where the particles are of the particle size of 150 microns and lower or at most 150 microns," all of the particles will pass through a sieve of the 150 micron size. Similarly, particles at most 50 microns and 50 microns and less are those which pass through a 50 micron sieve. The sieves, of course, have openings with diameters of 150 microns and 50 microns respectively. Similar definitions apply to all particle measurements given below.

According to the present invention, the botanicals which are used may be selected in order to provide desired agents in the tobacco smoke, intended to affect the patient, e.g., to reduce appetite, to modify circulation. To the extent that the botanicals contain toxic, poisonous or detrimental organic materials, these are removed by any conventional extraction process operating upon the slurry. Subsequent to such removal, we may add aromatic or flavoring substances or even pharmacologically active substances intended to affect the smoker. Of course, such additives should be of the type which remain intact in the smoking process and are carried by the smoke to the mucuous membranes of the smoker for entry into the biological process. The substances must be resistant to the heat generated during smoking. Additives may be provided to insure regularity of burning so that a smooth taste is assured and harsh gases do not regularly enter the buccal cavity.

According to an important feature of the present in vention, the milling process is carried out in a number of stages, the first stage being a blade-type coating or shredding in which the plant parts are comminuted to a maximum particle size of 2 cm. This shredding operation uses mechanically displaced blades and primarily a shearing action. In the second milling stage, the pieces generated by the first stage are dry-milled in an impact or hammer mill to a particle size of at most 150 microns. This coarse milling stage is followed by a drymilling stage of the jet pulverizer type in which the particles are entrained in a turbulent air stream and are therein comminuted to a particle size of at most 50 microns. The fine particle product is then slurried in water as noted earlier.

The wet-milling operation, according to the present invention, preferably takes place with moving milling surfaces and may employ milling disks, milling drums, milling rollers or balls. Advantageously the milling is carried out in a ball mill as described in the Austrian Patent No. 280,870 with a mobile packing of, for example, glass balls. We have found it to be desirable to cool the mill in order to prevent an undue rise in temperature (above 43C) with consequent loss of aroma by local overheating. The wet-milling stage is carried out to a maximum particle size of 5 microns and results in a substantially colloidal dispersion of the particles.

We have found that, in many cases, it is desirable to heat the slurry to a temperature of 70 to 100C over a period of to 30 minutes, when natural binders such as pectins are present in the botanicals, thereby activating these natural binders and allowing the quantity of binder additives to be reduced. When this is the case, we prefer that the slurry be heated autogeneously by friction during the wet-milling stage. The mill balls should have a starting diameter of 2 mm and may be of the type described in Austrian Pat. No. 280,870.

We have already noted that the invention is applicable to plants and plant parts of a wide variety of types as long as the botanical is free from woody parts or contains little wood. Suitable plants and plant parts are grasses, barks and greens, roots, seeds and greens, leaves, needles of fir trees, weeds, blossoms, vegetables, stems stalks and root branches, tips and the like. Preferably sprouts of plants, blossoms, leaves and the tender tips of roots are employed. The botanical may be fermented or nonfermented, dry or undry (green), should not contain any toxic or poisonous substances which cannot be subsequently removed. However we prefer to dry the botanical prior to comminution. Preferably the botanical mixture contains at least one of the following plant parts: lettuce leaves, lettuce ribs and stalks, tea leaves, tea stems, fir needles, fir stems, rose blossom petals. Poisonous and other detrimental components of the botanicals are preferably removed from the botanicals by treatingthe slurry at an optimum pH by steam distillation or by solvent extraction. Atropine, morphine, heroin and like toxic substances can thus be removed. Of course, when steroids and other pharmacologically active substances are present in nondetrimental quantities, they may be permitted to remain for promoting circulation, limiting appetite etc. More commonly, all such toxic substances are removed and, where pharmacologically substances are required, they are added in a subsequent stage. The addition stage may involve introduction of flavoring and aromatizing substances. As examples, for pharmacological active additives we may name menthol, nicotine and caffein. These and other known additives to tobacco and tobacco products and which are heatresistant and volatile are preferred in the smoke. The additives should be present in such low concentrations that they have no detrimental effect on the smoker.

The plasticizers which may be used, according to the present invention, include diethylene glycol, glycerine and sorbitol, the latter in a percent solution. As already noted, the presence of natural binders such as pectins may reduce the proportion of sodium carboxymethyl cellulose which may be added. It is also possible to add various chemicals, in amounts up to 5% by weight of the dry botanical, to promote binding or filmforming. The chemicals which may thus be added are ammonia, ammonium formate, potassium hydroxide. potassium carbonate, polyphosphates, citric acid and tartaric acid.

DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which the sole FIGURE is a flow diagram illustrating the invention.

SPECIFIC DESCRIPTION In block 1 of the drawing, we have represented the operation of gathering the botanicals or plant parts which are desirable for use in accordance with the present invention and drying the botanicals either naturally, i.e., in the open air, or artificially in the circulating airdrying oven or chamber. As noted earlier, the plant I v l l l le 1 53 we at 8 n J I ew eofi a B E E E i 5.6 .6 a; 3255.0 052? Shim 23: 5::

on 3 E EEQQ a2 a 20 32 m cow on ow @355553 3.25 mm mm 2238 255 11. mg 3.633 m cow moumenme m 3 m m mwmm oi u 2 mopwenmw m om l Tu .BEBZM o3 weteofim m E 92M 26153 N 2 1 ec im w ca 3333 $0 on I i t 1 I i v t v i i I I. i i i i i r I i v i v l v i i ii i. fi mm. I i i l i I t v i t v i i IIUHLIHOGZ w mm i t s a a u? o; w on 0292 w z I I i t I I t v i i v i I wall D i I i r I i r t i i i i t i v i i i i l r mpwaz m r l i i v I t t t i i i I v I i I ma F: i I i %-:\m::-m LO a V: 1 HCL- 3: 2 E

e: F :2 292: km 6E o WQBW Q $595.5 \2 1 s e g e ;36 M E 63 35 m ee 3 32303 mow I. E5 #022 $3 63 12 25 N meow, mwom aware: .2620 m ets N am 32 5 $22 595m x n: 32%: 5: $2 $552 a R om 0353 m QEE a QEEE m 2955 2 H t HQMQAH may be grasses,

parts which constitute the botanicals in the present invention and are gathered in step 1 bark, roots, seeds, grains, leaves, needles (fir tree), vegetable matter such as skin or vegetable pulp, weeds, blossoms, stalks and stems, root branches, tips nodules, 5 sprouts and parts thereof, as long as the plant or plant part is basically nonwoody. The plants or plant parts may be fermented or nonfermented and may contain undesirable proportions of .toxic or biologically active components for later removal, as will be apparent here- 10 inafter. Excellent results havebeen obtained with lettuce leaves, lettuce stacks and ribs, tea leaves, tea stems, fir needles, fir-tree stems, rose-blossom petals and mixtures thereof.

The dried botanicals are cut in step 2 into pieces with a maximum size of 2 cm by a conventional shredding apparatus, e.g., a rotary-blade cutter as described in pages 8 56 ff. of PERRYS CHEMICAL ENGI- NEERS HANDBOOK, McGraw Hill Book Company, New York, 1963. The comminuted botanicals are then fed into a dry-grinding stage 3 in which they are further comminuted to a particle size below 150 p. or less in stage 4. The particles are slurried with water in step 5, the water being supplied as'represented in block 13. The slurry is subjected to wet milling, in a ball mill as described in Austrian Pat. No. 280,870 to a particle size upto 5 microns.

The slurry is then treated at 7 to eliminate harmful substances which may be collected at 14 in the withdraw stage 7. The slurry may be treated with steam to steam-distill the harmful-substances, or may be subjected to solvent extraction. Steam-distillation may be carried out as described at page 13 20 of PERRYS CHEMICAL ENGINEERS HANDBOOK, while the solvent-extraction treatment may be carried out in accordance with the principles set forth at pages 14 to 14 69 of PERRYS CHEMICAL ENGINEERSS HANDBOOK. The product introduced into the stage 8 is thus a slurry free from or containing only a controlled amount of biologically active principles. The substances which can be removed in this manner from the slurry, can be atropins, morphine-type compounds, heroin, tannin and like steroids or toxins. When desirable, the removal process can be carried out in such manner as to leave a controlled proportion of any desired biologically effective substance. However, we prefer in stage 8 to blenclthe slurry with any additives at 15 which may be desirable. The additives may be flavoring or aromatizing substances, e.g., essential oils or pharmacologically effective compounds such as menthol, nicotine, or caffein.

After blending the slurry with such additives to establish the desired concentration of biologically active materials and other additives of the type mentioned above, namely, combustion controllers, foil or film stabilizers, plasticizers and the like, the slurry is spred upon a sheet-steel surface at SI, dried at 10 to a moisture content of about 2 percent, rehumidified to a moisture content of about 10 percent in stage 11 and stripped from the filmforming sheet at 12.

According to another feature of the invention, small quantities of the botanicals, ground to a particle size of- ,u. and less, can be admixed with the slurry at 16 in a maximum ratio of this additive to the dry weight of the botanicals in the slurry of 1:1. This increases the concentration of biologically active substances from the'naturally occurring botanicals. Similarly, portions of the dry-ground botanicals from stage 4 can be diverted to stage 8 as represented by line 17, or a portion of the slurry from stage 5 can be shunted past the extraction stage 6 into the final slurry 8 as represented by line 18.

EXAMPLE I 1 kg of starting material, consisting of 70% by weight tea leaves, 5 percent by weight potato skins, 12 percent by weight rose petals, and 13 percent by weight of tips of the anise root, is shredded to a particle size up to 2 cm, is dry-milled in an impact mill to a particle size of 150 t and less and is then further comminuted in a jet pulverizer to a particle size of 50 p. and less.

The milled product thus recovered is slurried in 4 liters of water and the slurry is then forced through a constantly agitated glass-ball packing for ball milling in a slurry state. The friction heat during the wet-milling operation is dissipated by cooling of the ball mill so that the temperature of the slurry does not exceed 43C. The particle size of the botanicals in the resulting dispersion is at most 5 p. and most of the particles are of colloidal dimensions, i.e., less than l ,u.. Into this dispersion, we mix 20 g of sodium carboxymethyl cellulose (binder) and 30 g of glycerine (plasticizer). The slurry is then cast onto a horizontal steel sheet, dired to a moisture content of 2% by weight. The dry foil is sprayed with water steam to a moisture content of by weight and the foil removed by a blade from the plate. The moisture content in all of the foregoing text is given in terms of the dry weight of the botanicals used. The elastic and coherent foil, which is optionally mixed with natural tobacco is then shredded in the manner of natural tobacco leaves and formed into cigarette, cigar and pipe tobacco.

The Table illustrates further Examples of the invention.

We claim:

1. A method of making a tobacco substitute which comprises the steps of comminuting a mixture of different low-wood parts of at least two different botanicals selected from the group which consists of lettuce, tea, fir, rose, tomato, thyme, sour cherry, melitot, stinging nettle, ebony, woodruff, maple, corn, fleabane, and to a particle size of at most 150a to form a heterogeneous mix; slurrying the botanical particles of said heterogeneous mix in water in a weight ratio of the botanicals to the water of lzl to 1:10; wet-milling the particles in the resulting slurry; mixing with said slurry 0.5 to 3% by weight of the dry botanicals of sodium carboxymethyl cellulose, 1 to 10% by weight of the dry botanicals of a plasticizer selected from the group which consists of sorbitol, glycerine and diethyleneglycol, 0 to 1% by weight of the dry botanicals of a formate salt, and O to 5% by weight of the dry botanicals of an aromatic and/or biologically active additive selected from the group which consists of menthol, nicotine and caffeine to produce a film-forming composition; spreading said film-forming composition; drying said film-forming composition to produce a tobacco-substitute foil; and controlling the drying of said foil to maintain the moisture content thereof between 1 to 15% by weight of the foil, the botanicals being comminuted in a first stage by jet pulverization to a particle size of at most y. prior to slurrying, the slurry containing the particles from said third stage being milled by passing it through a milling-grains packing whereon the milling-grains roll against one another, any toxic substance contained in said botanicals being removed by steam distillation or solvent extraction prior to spreading of said filmforming composition. 

